Installed the 380mm brakes last night
08-14-2009, 11:42 AM
#18
Drifting
Join Date: Nov 2006
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You guys should be aware that none of the Porsche 993 based racecars (Cup, RSR, or GT2) used RS rear calipers. Generally using RS rear calipers results in way too much rear brake when using "normal" 332 mm front discs.
With 380mm discs, I felt the RS rear calipers were still too much on an RSR with 14 inch wide back tires.
Maybe a better solution is to use Turbo rear calipers and remove the pressure limiting valves on the rear brake lines. This is how all the race cars were set up.
They also used the RS booster (which is quite expensive but REALLY helps the brake feel) and a different ABS ECU. The ECU is also very expensive and requires some wiring changes.
Chris Cervelli
Spline Technologies
With 380mm discs, I felt the RS rear calipers were still too much on an RSR with 14 inch wide back tires.
Maybe a better solution is to use Turbo rear calipers and remove the pressure limiting valves on the rear brake lines. This is how all the race cars were set up.
They also used the RS booster (which is quite expensive but REALLY helps the brake feel) and a different ABS ECU. The ECU is also very expensive and requires some wiring changes.
Chris Cervelli
Spline Technologies
08-14-2009, 11:55 AM
#20
Three Wheelin'
Thread Starter
Ugh the BBS still didn't fit with the 255/35 hoosier so I need to go from a 2.5 inch lip to a 2 inch lip now. The wheel hits the bumper when you turn it inside 
Should fit fine once I get that new lip on order at least BBS has them in stock!
Should fit fine once I get that new lip on order at least BBS has them in stock!
08-14-2009, 03:06 PM
#21
I turned the lettering on my RS calipers brown at my last event so some sort of ducting will be going on there shortly. No matter what they are going to get alot hotter due to the size but that doesn't mean a little air can't help 
What gives with the times going up Brad?! Surely there is a mod that can fix that
What gives with the times going up Brad?! Surely there is a mod that can fix that
Well the latest 'mod' is going to have to be some good old fashioned instruction.
Things are looking like a go for having Chris do some remedial drivers skill training in a month or two at mid-ohio.
I know those rims fit my car w/o any rubbing--bbs front 10" wide rims using 8.5" inside, 1.5" outside halves (52mm offset). Running -3.3 camber up front.
08-14-2009, 03:19 PM
#22
Three Wheelin'
Thread Starter
Sounds like you're doing some serious driving there smoking the calipers!
Well the latest 'mod' is going to have to be some good old fashioned instruction.
Things are looking like a go for having Chris do some remedial drivers skill training in a month or two at mid-ohio.
I know those rims fit my car w/o any rubbing--bbs front 10" wide rims using 8.5" inside, 1.5" outside halves (52mm offset). Running -3.3 camber up front.
Well the latest 'mod' is going to have to be some good old fashioned instruction.
Things are looking like a go for having Chris do some remedial drivers skill training in a month or two at mid-ohio.
I know those rims fit my car w/o any rubbing--bbs front 10" wide rims using 8.5" inside, 1.5" outside halves (52mm offset). Running -3.3 camber up front.
My 10inch fronts had an 2.5 inch lip and a 7.5 inch barrel and it hits the front bumper when I turn the wheel with 3.25 camber. I'm going to run a 2 inch lip and that should fix it. Since I'm going to run a 255 there is no real reason to get a new new inner barrel to make it 10 inches total if that makes sense. Maybe I'm running too much castor which pushes the wheel up the front of the car? It "barely" doesn't fit and I cant get a smaller tire in there so this is my next option. The kelly moss alignment might fix it but I don't have the luxury of time to figure it out and will throw a smaller lip on there to make sure nothing gets in the way of my RA time
Here are a couple of pictures the first one isn't touching the bumper but you can see how tight the fit is. 
08-16-2009, 01:34 AM
#25
Three Wheelin'
Thread Starter
I sourced these from Steve at rennsport. Found them for little cheaper than he was offering but considering all the help via phone and email I would always rather give him the business.
Give him a call he will set you up, just be ready to purchase some new rims since only a handful will clear 380's
Give him a call he will set you up, just be ready to purchase some new rims since only a handful will clear 380's
04-12-2019, 08:18 PM
#26
Rennlist Member
Nice set-up! Can you post a pic of the caliper mounting bracket on your upright.
Im doing a similar conversion with 993 RSR parts but I cant source the adaptor bracket.
Thanks.
Im doing a similar conversion with 993 RSR parts but I cant source the adaptor bracket.
Thanks.
